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Evaluation Of Strain Distortion Correction Protocol Using Scanning Electron Microscopy And Digital Image Correlation, Alexandra Mallory, Alberto Mello, Michael Sangid 2016 San Diego State University

Evaluation Of Strain Distortion Correction Protocol Using Scanning Electron Microscopy And Digital Image Correlation, Alexandra Mallory, Alberto Mello, Michael Sangid

The Summer Undergraduate Research Fellowship (SURF) Symposium

Scanning electron microscopy in combination with digital image correlation (SEM-DIC) is a useful technique for measuring strain in materials at the micro-scale. In particular, it can be used to identify micro-scale strain localizations that are the precursor to material failure. While SEM produces high resolution images of the microstructure, the images also contain a large amount of distortion that, during DIC, will result in distorted strain values that require correction. In this project, a nickel-based alloy underwent cyclic mechanical fatigue at three different high temperatures to a targeted maximum strain. Scanning electron microscopy imaging was done on a 200x150μm area ...


Metamodels Of Residual Stress Buildup For Machining Process Modeling, Stuart B. McCrorie, Michael Sangid 2016 Purdue University

Metamodels Of Residual Stress Buildup For Machining Process Modeling, Stuart B. Mccrorie, Michael Sangid

The Summer Undergraduate Research Fellowship (SURF) Symposium

In the process of machining materials, stresses, called residual stresses, accumulate in the workpiece being machined that remain after the process is completed. These residual stresses can affect the properties of the material or cause part distortion, and it is important that they be calculated to prevent complications from arising due to the residual stresses. However, these calculations can be incredibly computationally intensive, and thus other methods are needed to predict the residual stresses in materials for quick decision-making during machining. By using metamodels - a method of representing data where few data points exist - we can achieve an accurate prediction ...


Statistical Impact-Echo Analysis Using Bag-Of-Echoes Model For Concrete.Pdf, Jiaxing Ye 2016 National Institute of Advanced Industrial Science and Technology

Statistical Impact-Echo Analysis Using Bag-Of-Echoes Model For Concrete.Pdf, Jiaxing Ye

Jacky Yin

In recent years, advancement in information technologies, i.e. cloud service and high speed wireless network, greatly facilitate the large collection of structural health monitoring (SHM) data. In order to effectively exploit massive sensor data for accurate condition assessment of infrastructures, there has been increasing interest in application of statistical pattern recognition methods in the field of SHM. This paper addresses development of efficient pattern analysis scheme for impact-echo test, which is one of the most conventional nondestructive test (NDT) methods. The proposed scheme stems from Bag-of-feature (BoF) model, which has been successfully applied for natural language processing and computer ...


Statistical Impact-Echo Analysis Using Bag-Of-Echoes Model For Concrete.Pdf, Jacky Yin 2016 Hongkong Baptist university

Statistical Impact-Echo Analysis Using Bag-Of-Echoes Model For Concrete.Pdf, Jacky Yin

Jacky Yin

In recent years, advancement in information technologies, i.e. cloud service and high speed wireless network, greatly facilitate the large collection of structural health monitoring (SHM) data. In order to effectively exploit massive sensor data for accurate condition assessment of infrastructures, there has been increasing interest in application of statistical pattern recognition methods in the field of SHM. This paper addresses development of efficient pattern analysis scheme for impact-echo test, which is one of the most conventional nondestructive test (NDT) methods. The proposed scheme stems from Bag-of-feature (BoF) model, which has been successfully applied for natural language processing and computer ...


Predicting Flexural Strength Of Composite Honeycomb Core Sandwich Panels Using Mechanical Models Of Face Sheet Compressive Strength, Nicholas Bruffey, William Shiu 2016 California Polytechnic State University, San Luis Obispo

Predicting Flexural Strength Of Composite Honeycomb Core Sandwich Panels Using Mechanical Models Of Face Sheet Compressive Strength, Nicholas Bruffey, William Shiu

Materials Engineering

The design process at Zodiac Aerospace requires the ability to accurately predict the strength of a composite honeycomb core sandwich panel to adhere to strict FAA regulations. The most common failure mode in long beam composites is in compression. Following ASTM D7249 for a four-point bend test of a long beam flexural test, a mechanical model has been developed that relates the compressive strength of glass fiber face sheets to the flexural strength of the sandwich panel. Zodiac does not currently have data on the compressive strength of the face sheets, so testing was performed to find this property. Asymmetric ...


Effects Of Curing Cycle And Loading Rates On The Bearing Stress Of Double Shear Composite Joints, Mateja Andrejic 2016 California Polytechnic State University - San Luis Obispo

Effects Of Curing Cycle And Loading Rates On The Bearing Stress Of Double Shear Composite Joints, Mateja Andrejic

Master's Theses and Project Reports

In the last few decades, there has been a shift to using more lightweight materials for the potential of fuel consumption reduction. In the Aerospace Industry, conventional metal structures are being replaced by advanced composite structures. The major advantage of an advanced composite structure is the huge reduction in the number of parts and joints required. Also composite materials provide better resistance to creep, corrosion, and fatigue. However, one cannot eliminate all the joints and attachments in an aircraft’s structure. Eliminating structural joints is impractical in present-day aircraft because of the requirements for inspection, manufacturing breaks, assembly and equipment ...


Implementation Of A Large Solar Collector For Solar Light Energy, Skye Leake, Thomas McGuire, Michael Hirsch, Michael Parsons, Jeremy Straub, Scott Kerlin 2016 Selected Works

Implementation Of A Large Solar Collector For Solar Light Energy, Skye Leake, Thomas Mcguire, Michael Hirsch, Michael Parsons, Jeremy Straub, Scott Kerlin

Jeremy Straub

The challenge of providing large amounts of electrical energy for spacecraft over the course of long du-ration missions has long been an area of aerospace research. This need is particularly pronounced for a solar-powered in-space 3D printer [1]. Solar flux is commonly collected with solar panels for powering spacecraft. This is a reliable and safe method for electricity generation. Other generation methods, such as onboard nuclear power, present safety concerns.
Large solar collectors also have other benefits over alternate electricity generation methods. Theses benefits include using the solar collector as a solar shade, and using the back side of the ...


Origami Style Solar Panels With Development Of Dual Purpose Integrated Phased Array Communications System, Alexander Holland, Wilson Lysford, Jens Pearson, Jeremy Straub, Scott Kerlin 2016 Selected Works

Origami Style Solar Panels With Development Of Dual Purpose Integrated Phased Array Communications System, Alexander Holland, Wilson Lysford, Jens Pearson, Jeremy Straub, Scott Kerlin

Jeremy Straub

The purpose of this poster is to explore space based power generation capabilities and transmission based on using Origami Style Solar and Antenna Panels (OSSAP). Basically, the OSSAP is designed to be a new type of origami panels that operate differently from conventional solar panels and antennas. They should be easier to manufacture and usable on a wide range of spacecraft. They have a lower launch volume and mass; however, once in space the system unfolds to provide a large surface area. The unfolding can be done in several ways including using a pressurized gas system for deployment. This method ...


In-Space 3d Printing Scientific Remote Sensing Missions, Michael Hirsch, Thomas McGuire, Skye Leake, Michael Parsons, Jeremy Straub, Scott Kerlin 2016 Selected Works

In-Space 3d Printing Scientific Remote Sensing Missions, Michael Hirsch, Thomas Mcguire, Skye Leake, Michael Parsons, Jeremy Straub, Scott Kerlin

Jeremy Straub

Currently, remote sensing missions involve the pro-duction of complex and deployable structures that must withstand the forces involved with launching and assembly in space. To combat this, the technology of 3D printing [1] can be applied. Additive manufacturing technology has improved greatly in the recent past, al-lowing for the possibility of in-space 3D printing [2].
By taking the concepts of 3D printing and using them for scientific remote sensing missions [3], it is possible to print structures that would be otherwise impossible, due to constraints for terrestrial construc-tion, launch and deployment. A design is proposed in [2] that will both ...


National Defense 3d Space Printing, Michael Parsons, Thomas McGuire, Michael Hirsch, Skye Leake, Jeremy Straub, Scott Kerlin 2016 Selected Works

National Defense 3d Space Printing, Michael Parsons, Thomas Mcguire, Michael Hirsch, Skye Leake, Jeremy Straub, Scott Kerlin

Jeremy Straub

National defense is a strategic priority that is challenged everyday. A variety of humans and systems protect the United States from global terrorism. Space-craft are key components of the national defense. They provide surveillance, communications and navigation and other services.
These craft can be augmented using in-space 3D printing. An in-space 3D printer could be used for applications relevant to attacking or defending spacecraft or terrestrial targets. Currently, weapons must be launched from the ground. A weapon can be launched from an ideal point in orbit, on the other, hand, enjoys a variety of benefits. This poster considers how in-space ...


Design For An In-Space 3d Printer, Thomas McGuire, Michael Hirsch, Michael Parsons, Skye Leake, Jeremy Straub, Scott Kerlin 2016 Selected Works

Design For An In-Space 3d Printer, Thomas Mcguire, Michael Hirsch, Michael Parsons, Skye Leake, Jeremy Straub, Scott Kerlin

Jeremy Straub

Getting into space is a key constraint of current space mission designs. Launching spacecraft or components for spacecraft into space requires large amounts of structural components and packaging to secure it, adding additional mass and cost to the launch. Being able to bypass this current system would allow more frequent and cheaper space missions. An in space 3D printer is key to this. By placing a 3D printer in orbit, raw material (which requires less support and packaging to ship) can be sent to space. Craft and components can be fabricated on demand. This also allows craft to be designed ...


Effect Of Low Velocity Impact On The Vibrational Behavior Of A Composite Wing, Richard M. de Luna 2016 California Polytechnic State University, San Luis Obispo

Effect Of Low Velocity Impact On The Vibrational Behavior Of A Composite Wing, Richard M. De Luna

Master's Theses and Project Reports

Impact strength is one of the most important structural properties for a designer to consider, but it is often the most difficult to quantify or measure. A major concern for composite structures in the field is the effect of foreign objects striking composites because the damage is often undetectable by visual inspection. The objective for this study was to determine the effectiveness of using dynamic testing to identify the existence of damage in a small scale composite wing design. Four different impact locations were tested with three specimens per location for a total of 12 wings manufactured. The different impact ...


Cryogenic Processing Of Al 7050-T7451 Alloy For Improved Surface Integrity, Bo Huang 2016 University of Kentucky

Cryogenic Processing Of Al 7050-T7451 Alloy For Improved Surface Integrity, Bo Huang

Theses and Dissertations--Mechanical Engineering

Al 7050-T7451 alloy with good combinations of strength, stress corrosion cracking resistance and toughness, is used broadly in the aerospace/aviation industry for fatigue-critical airframe structural components. However, it is also considered as a highly anisotropic alloy as the crack growth behavior along the short transverse direction is very different from the one in the long transverse direction, due to the inhomogeneous microstructure with the elongated grains distributed in the work material used in the sheet/plate applications. Further processes on these materials are needed to improve its mechanical and material properties and broaden its applications.

The material with ultra-fine ...


Simulating Ut Measurements From Bolthole Cracks, Robert J. Grandin, Timothy A. Gray, Ronald A. Roberts 2016 Iowa State University

Simulating Ut Measurements From Bolthole Cracks, Robert J. Grandin, Timothy A. Gray, Ronald A. Roberts

Center for Nondestructive Evaluation Conference Papers, Posters and Presentations

Analytical computer models of UT measurements are becoming more prominent in evaluating NDEmethods – a process known as Model Assisted Probability of Detection, or MAPOD. As inspection requirements become more stringent, the respective models become more complex. An important application for aerospace structures involves inspection for cracks near boltholes in plate and layered structures. This paper describes a project to develop and validate analytical models for bolthole crackinspection, as well as to implement and demonstrate those models within an integrated graphical interface which can be used to simulate these inspections. The work involves a combination of approximate, paraxial, bulk-wave models as ...


Polyacrylonitrile Copolymers: Effects Of Molecular Weight, Polydispersity, Composition, And Sequencing On Thermal Ring-Closing Stabilization, Jeremy D. Moskowitz 2015 University of Southern Mississippi

Polyacrylonitrile Copolymers: Effects Of Molecular Weight, Polydispersity, Composition, And Sequencing On Thermal Ring-Closing Stabilization, Jeremy D. Moskowitz

Dissertations

Controlled polyacrylonitrile (PAN)-based carbon fiber precursors with defined molecular weights, polydispersities, compositions, and architectures have been prepared for their study on thermal ring-closing stabilization behavior. PAN and its copolymers of number average molecular weights exceeding 170,000 g/mol were successfully synthesized via low temperature reversible addition-fragmentation chain transfer (RAFT) polymerization. RAFT polymerizations of PAN-based precursors were compared to conventional free radical solution polymerizations with a focus on the effects of molecular weight and polydispersity on structural evolution and cyclization efficiency. When RAFT polymerization was extended to copolymers, it was found that RAFT copolymers achieved greater cyclization intensities and ...


Volatile Condensible Material Deposition In Leo Simulated Environment, Jinya Pu 2015 University of Nebraska-Lincoln

Volatile Condensible Material Deposition In Leo Simulated Environment, Jinya Pu

Theses and Dissertations from Electrical & Computer Engineering

Room Temperature Vulcanized (RTV) silicone and compounds are widely used in outer-space for bonding or potting spacecraft components. In geosynchronous equatorial orbit (GEO), the silicone may outgas species which can condense on optically sensitive surfaces and degrade their performance, therefore shortening the lifetime of spacecraft. In low-earth-orbit (LEO), the silicone rubber is subject to an energetic and corrosive environment. Atomic oxygen (AO) and ultraviolet radiation can cause abrasion and degradation of the silicone rubber, cause changes in existing condensed VCM films and affect the properties of VCM films condensing in this atmosphere. Experiments were performed to simulate GEO conditions. In ...


Comment On Faa Rule Revision - Transport Category Aircraft, Paul Eschenfelder, Valter Battistoni 2015 Embry Riddle Aeronautical University - Daytona Beach

Comment On Faa Rule Revision - Transport Category Aircraft, Paul Eschenfelder, Valter Battistoni

Paul F. Eschenfelder

No abstract provided.


Characterizing Strain Accumulation, Residual Stress, And Microstructure Of Additive Manufactured Materials, Hannah K. Woods, Todd A. Book, Catalina Parada, Michael D. Sangid 2015 Purdue University

Characterizing Strain Accumulation, Residual Stress, And Microstructure Of Additive Manufactured Materials, Hannah K. Woods, Todd A. Book, Catalina Parada, Michael D. Sangid

The Summer Undergraduate Research Fellowship (SURF) Symposium

Additive Manufacturing (AM) is a rapidly evolving fabrication technology beneficial for its cost-saving potential to produce complex, low-volume shapes. However, AM materials are currently limited to nonstructural applications due to variability in their structural integrity, particularly their fatigue lives. IN718, Ti64, and Al10MgSi specimens manufactured by Direct Metal Laser Sintering (DMLS) were characterized based on variation of post-processing techniques and build direction. To understand the impact of each variable, surface roughness, hardness, residual stresses, microstructure, and strain accumulation in response to Low Cycle Fatigue (LCF) were studied. The use of Electron Backscatter Diffraction (EBSD) provided grain orientation and grain size ...


Identifying And Correcting Biases In Digital Image Correlation At Multiple Length Scales, Catalina Parada, Alberto W. Da Silva Mello, Michael D. Sangid, Hannah K. Woods, Samuel E. Otto 2015 Iowa State University

Identifying And Correcting Biases In Digital Image Correlation At Multiple Length Scales, Catalina Parada, Alberto W. Da Silva Mello, Michael D. Sangid, Hannah K. Woods, Samuel E. Otto

The Summer Undergraduate Research Fellowship (SURF) Symposium

Accurate strain measurement at grain and sub-grain levels is important to predict and understand crack initiation during fatigue of materials. During cyclic loading, low magnitude strain is accumulated in the material and any distortion in the images can lead to inaccurate strain measurements and false prediction of the material’s behavior. Digital Image Correlation (DIC) is a reliable tool used to measure strain localization by correlating images before, during, and after cyclic loading. DIC tracks the deformation of nano/micro-scale patterns placed on the surface of the specimens to determine strain fields. However, DIC software does not account for biases ...


The Robert H. Goddard Papers, Robert H. Goddard 2015 Clark University

The Robert H. Goddard Papers, Robert H. Goddard

Archives and Special Collections Finding Aids

Dr. Robert H. Goddard was a member of the Clark Physics Department for 29 years. Foremost American pioneer of rocket research, he laid the technical and theoretical foundations for many of the developments in long-range rockets, missiles, satellites and space flight, which collectively put us into the Space Age.

The collection includes correspondence, diaries, journals, patent applications and awards, reports, and photographs. The collection also includes original paintings by Dr. Goddard.


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